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A New Bridge in 25 Hours

To build a bridge linking U.S. Navy Support Activity Bahrain to the U.S. Navy Port Facility, and not disrupt vehicle traffic during construction, there was only one solution—and it was something the project’s executing agency had never done before.

By  Ali Chahine, P.E., M.SAME   


The P-954 Flyover Bridge, linking U.S. Navy Support Activity Bahrain to the U.S. Navy Port Facility, was the first “build, lift, move and install” bridge project in the Middle East. PHOTOS COURTESY CONTRACK WATTS INC.

The P-954 Flyover Bridge, linking U.S. Navy Support Activity Bahrain to the U.S. Navy Port Facility, was the first “build, lift, move and install” bridge project in the Middle East. PHOTOS COURTESY CONTRACK WATTS INC.


 

A major challenge confronting the Middle East District of the U.S. Army Corps of Engineers (USACE) on its Waterfront Development Phase III project was how it would link U.S. Navy Support Activity Bahrain to the nearby U.S. Navy Port Facility. The obstacle to overcome was the busy, six-lane Khalifa Bin Salman Causeway that divides the two base locations. This major traffic corridor, with a vehicular volume comparable to the Beltway surrounding Washington, D.C., is a crucial artery for area business and commerce. 

USACE initially planned to construct a four-span or three-span pre-stressed concrete bridge. The idea being that a girder bridge would be the most cost-effective approach. This option required placement of bridge piers that would necessitate lane closures—significantly impacting traffic and elevating the safety risks for both workers and drivers caused by working in heavy traffic congestion. Evaluating the bridge options, Bahrain officials considered the standard “build in place” bridge solution unacceptable, since it would disrupt and impact causeway traffic for months.

U.S.-based designer HNTB then proposed an alternative structure, the Flyover Bridge, and presented to the stake-holders the constructability and benefits of arch-type structures. Viewing the 3D renderings of the proposed arch solution, Bahraini officials visualized the more aesthetic look of the new single-span bridge, and learned how it would be constructed off site, how the structure would be placed into its permanent location, and why the design provided the best value.

Contrack International Inc., (now Contrack Watts Inc.), which was the primary contractor awarded the accelerated bridge construction project, led Contrack Nass JV and a multinational team to deliver the P-954 Flyover Bridge, the first “build, lift, move and install” bridge project of its kind in the Middle East, and also for USACE.

 

INFRASTRUCTURE THAT MOVES

Construction of the single-span, two-lane, P-954 Flyover Bridge began in September 2012. The work on the 122.5-m long, 16-m wide and 27.5-m tall tied-arch cable suspension bridge, with its roadway and pedestrian walkway of post-tensioned concrete, occurred 250-m away from where its permanent location would be.

Building and then moving the 2,860-T bridge into place over the causeway utilizing self-propelled modular transporters demanded thorough coordination. Experienced teams erected the tied-arch cable suspension bridge, on bearing within tolerance level and within the allocated time.

The bridge was designed and built to withstand the rigors of its journey into position. Early in the project, the team had held a coordination meeting to identify, discuss and resolve potential technical and safety issues that might impact the schedule, the on-site team and the traveling public. Before the move, lifting beams were installed at each end. The bridge was suspended from the beams using 2-in diameter high strength rods at the four lifting points. In addition to the lifting beam installation, Contrack’s team completed an analysis on the causeway pavement to ensure it could withstand the bridge’s weight.

The move was accomplished with four 12-axle self-propelled modular transporters using a series of translational and rotational maneuvers. Team members used computer modeling and precise incremental maneuvers, manually controlling each pair of mobile transporters at opposite ends of the bridge and adjusting and turning individually each set of wheels, 48 sets per transporter. This was required before each segment of the move. An operator used computer-driven controls to set position of the axles for that particular transport. The pairs of 12-axle transporter units on each corner lifted the bridge at its bearing points and safely moved it onto pre-constructed abutments.

A huge concern for engineers was minimizing the stress the move placed on the completed bridge, with its concrete roadway and walkway. To minimize stress levels, engineers monitored tire pressure using computerized sensors. They also mounted laser pointers and corresponding 4-in diameter targets along the bridge’s length and width, to ensure the precise alignment during turning movements.

While a number of mechanical failures caused unexpected delays, including two broken hydraulic cylinders that had to be replaced in one of the transporters, the bridge was moved into place overnight Jan. 30–31, 2014. The total duration to execute the move was 25 hours between the time the self-propelled modular transporter wheels began rolling to the time the bridge was lowered and set in the final service location on the abutments. The total causeway closure time was 11 p.m. to 9 a.m.

 

INTERNATIONAL COORDINATION

The international team faced, and overcame, several challenges posed by the project. Both HNTB and Contrack International worked closely with the project’s stakeholders: Naval Facilities Engineering Command Europe Africa Southwest Asia (based in Italy), host nation officials of the Bahrain Ministry of Works, and the executing agent, USACE Middle East District. Contrack led a team of industry experts from seven different countries to closely collaborate to build and move the bridge. To achieve clear communications, the joint venture team established that English, the common language for all team members, would be used on site. All project members, including subcontractors, also were required to gain orientation training before stepping on site. Orientation entailed outlining expectations, policies and procedures, and safety training.

The orientation efforts and a commitment to strong project management and safety training and awareness throughout made a difference. During the bridge construction and the move, with a maximum of 150 personnel on site at once, the project team achieved a total of 308,000 work-hours with no lost time incidents.

The variances in cultures and construction experience among the project team members necessitated the major issue decisions to be made by Contrack’s management team. Organization meetings and workshop sessions required the team to provide solid scheduling and full coordination to accommodate both the project schedule as well as the availability in dates and times for executive team members and project participants traveling to the project site from Belgium, Abu Dhabi, Italy, Spain, and the United States.
The team also overcame logistical and scheduling challenges involved in procuring building materials, shipped from both Middle Eastern and European countries. Anticipating potential delays in shipping or customs inspections, and adapting to any changes, the team procured building materials that were shipped from Dubai, Italy, Belgium and Turkey.

 


The team also overcame logistical and scheduling challenges involved in procuring building materials, shipped from both Middle Eastern and European countries. Anticipating potential delays in shipping or customs inspections, and adapting to any changes, the team procured building materials that were shipped from Dubai, Italy, Belgium and Turkey. 


 

ACHIEVING SUCCESS

The P-954 Flyover Bridge is a more aesthetically pleasing solution that reduced the causeway closure time from several months to mere hours, minimizing commercial and public traffic disruptions. The off-site construction also resulted in safer working and traveling conditions. Additional benefits now include significantly reduced travel times between sites, improved security at access and entry points, and estimated savings of $650,000 annually in the Navy’s transportation costs.

The first “build, lift, move and install” bridge project in the Middle East was an unqualified success.

 


 

Ali Chahine, P.E., M.SAME, is Project Manager, Contrack Watts Inc.; +965-2221-64-23, or This email address is being protected from spambots. You need JavaScript enabled to view it..

Laura Luger, M.SAME, Contrack Watts Inc., contributed to this article.